In an electric field the acceleration of an electron is
1.a = mE/e
2.me/E
3.a = eE/m
4.e/mE
In the absence of an electric field the free electrons in a metal move
1.in the same direction
2.at a steady speed
3.in opposite directions
4.at random
In the presence of an electric field the free electrons
1.move in the direction of the electric field
2.move in all random directions
3.move at a constant speed
4.get accelerated in the direct of electric field
In the presence of an electric field the free electrons get deflected in different directions due to
1.external field
2.nuclear forces
3.random forces
4.coulomb forces
The average relaxation time is
1.the time during which the electrons relax in between collisions
2.the time over which the electrons get accelerated
3.the time taken for scattering
4.the time taken for deflection
The current is called a steady current when
1.the electrons flow in the same direction
2.the number of electrons in the flow is constant
3.the electrons flow in all directions
4.the rate of flow of electrons is constant
The current through a conductor I is equal to
1.nAeE ?/m
2.nAe2E ?/m
3.nAe2E ?/n
4.nAeE ?/n
The direction of the conventional current corresponds to the direction in which
1.negative charges flow
2.positive charges flow
3.Neutrons flow
4.mesons flow
The drift velocity of the electrons is given by Vd =
1.Ee ?2
2.e/m. ?
3.Ee/ ?. M
4.eE/m. ?
The electric current I is related to Q and t as
1.I = Qt
2.I = t/Q
3.I = Q/t
4.I = Qt2
The electric current in a conductor is measured based on
1.the number of free electrons available
2.the rate of flow of electrons
3.the quantity of charge flow
4.resistance of the conductor
The electric current is due to
1.random motion of electrons
2.drift velocity of electrons
3.Coulomb force between electrons and proton
4.repulsive force between free electrons and other electrons in an atom
The electromotive force
1.is a force
2.is work done
3.produces free electrons
4.is an electric field produced by current flow
The electron current and the conventional current
1.flow in the same direction
2.flow in the opposite direction
3.do not coexist
4.coexist
The expression for the electric current is
1.nAvde/m
2.nAvdE/m
3.nAvde
4.nAvdE
The external force that makes the free electrons to move in a conductor is
1.magnetic force
2.Lorentz force
3.Coulomb�s force
4.electromotive force
The flow of electric current in a conductor is due to12.
1.the Coulomb force on free electrons
2.the Lorentz force on electrons
3.the low resistivity of a conductor
4.the potential difference across the ends of a conductor
The maximum speed of free electrons in metal is of the order of
1.109 cm/s
2.107 cm/s
3.106 m/s
4.105 cm/s